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πŸŒ‹ Planet Earth πŸ’Ž Rocks and minerals

Minerals

Rocks are made of minerals. A large piece of granite contains small pieces of hornblende, feldspar (aluminum silicate), quartz and mica. These minerals are shown separately in the pictures (left).
Rocks are made of minerals. A large piece of granite contains small pieces of hornblende, feldspar (aluminum silicate), quartz and mica. These minerals are shown separately in the pictures (left).

πŸ“– In short

Minerals are the natural solid materials that rocks are made of. Every rock on Earth is made of one or more minerals, and even soil contains tiny bits of minerals. Salt, quartz, gold and diamond are all minerals.

🀩 Did you know?

  • There are about 3000 kinds of minerals, but only about a hundred are common.
  • A mineral has the same chemical makeup wherever it's found.
  • Quartz is one of the most common minerals on the Earth's surface.
  • Salt is made of tiny cube-shaped crystals. Look at them with a magnifying glass!

πŸ”Ž Find out more

🌟 Orderly crystals

A mineral's atoms are arranged in a precise repeating pattern, so many minerals take beautiful geometric shapes called crystals, like cubes or six-sided columns.

πŸ” How do we identify them?

Scientists identify minerals by their color, shine and hardness, by the color of the streak they leave when rubbed on a white tile, and by the way they break.

πŸ’‘ Hard and soft

Some minerals are very soft, like talc, which you can scratch with your fingernail and which is used to make baby powder, and some are very hard, like diamond.

🎯 Minerals in our lives

We use minerals every day: salt in food, gypsum in walls, quartz in watches and glass, and iron and copper ores in machines and wires.

πŸ“Έ More pictures

Some minerals
Some minerals
Common identification tests. A mineral's hardness is tested by scratching it with the minerals of the Mohs scale, shown in the table. The streak test (middle picture) leaves a red streak: the mineral is rubbed on rough porcelain and the streak wiped with a finger. (Left) calcite splits into blocks, while mica splits into thin sheets.
Common identification tests. A mineral's hardness is tested by scratching it with the minerals of the Mohs scale, shown in the table. The streak test (middle picture) leaves a red streak: the mineral is rubbed on rough porcelain and the streak wiped with a finger. (Left) calcite splits into blocks, while mica splits into thin sheets.
How atoms are arranged in minerals
How atoms are arranged in minerals

🧩 Test yourself

1 What do we call the geometric shapes a mineral takes?

2 Which very soft mineral is used to make baby powder?

3 There are about ?? kinds of minerals, but only about a hundred are common.

4 Which picture shows β€œMinerals”?

πŸŒ‹ Discover more